The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 24, 1998
Filed:
Apr. 05, 1995
Donald Lupo, Frankfurt, DE;
Josef Salbeck, Kelkheim, DE;
Hermann Schenk, Hofheim, DE;
Thomas Stehlin, Kriftel, DE;
Roland Stern, Wiesbaden, DE;
Arno Wolf, Mainz, DE;
Hoechst Aktiengesellschaft, Frankfurt, DE;
Abstract
Use of spiro compounds of the formula (I) ##STR1## where K.sup.1 and K.sup.2 are, independently of one another, conjugated systems, in electroluminescence devices. Preferred compounds of the formula (I) are 9,9'-spirobifluorene derivatives of the formula (II) ##STR2## where the benzo groups can be substituted independently of one another. Compounds of the formula (I) have a good solubility in customary organic solvents, improved film-forming properties and a significantly reduced tendency to crystallize. The production of electroluminescence devices is thereby made easier and their service life is increased.